Print PageDeveloping effective methods to restore the degraded ecosystem and eradicate the reinvasion over the long term are crucial task for restoration ecologists. Many studies have focused on the possibility of restoring a degraded ecosystem by altering light availability in the ecosystem. However, the role of light control in the restoration of mangrove ecosystems remains unclear. Sonneratia apetala Buch-Ham. is an exotic mangrove planted extensively on tropical and partly subtropical seashores in China. It is the preferred choice for use in mangrove restoration, but the ecological risks involved in using this plant are highly uncertain. However, how to make appropriate management of this species and accelerate the succession from S. apetala community to native mangrove community are poorly studied. We hypothesized that lowering the light availability during forestation will inhibit the growth of exotic S. apetala and thereby enhance the competiveness of native Aegiceras corniculatum (L.) Blanco. To investigate the effect of light control on the restoration of native mangrove ecosystems, we simulated two levels of irradiance of the S. apetala understory in the greenhouse. For each irradiance treatment, three levels of competition between the two mangroves were used: no competition, intraspecific competition and interspecific competition.
Results/Conclusions
Compared with native A. corniculatum, S. apetala showed a significantly higher growth rate in height and biomass accumulation. It also exhibited competitive inhibition under the high-light condition. The shading treatment significantly reduced its height, total biomass and biomass allocation to leaves by 61.31%, 71.0% and 76.2%, respectively, whereas the growth of A. corniculatum was not affected. The shading treatment produced no competitive resistance effects involving the two mangroves. The results suggested that lowering light availability could inhibit the growth of S. apetala and increase the competitiveness of A. corniculatum. Manipulating the light availability by controlling the density of planting could be an effective strategy to restore the degraded wetland habitat and reestablish the native mangrove forest.
